Means for flaring tubing



March 9, 1948. l Y. J. R. wELsHMAN 2,437,285

' MEANSl FOR FLARING TUBlNG Filed Noir. 11, 1945 Patented Mar. 9, 1,948

MEANS FOR FLARING TUBING James R. Welshman, Cranston, R. I., assignor toGrinnell Corporation, Providence, R. I., a corporation of DelawareApplication November 11, 1943, Serial No. 509,931

4 Claims.

This invention relates to improvements in a method of and means forflaring tubing. More especially it has to do with the formation of 'atapering flared portion at the end of tubing so that the tubing may beengaged by a flared i'ltting,

My improved method and means are particularly adapted for llaring'tubingwhich has a weak longitudinal seam, or `similar longitudinal weakness,likely to produce a split in the tube wall when an attempt is made tovflare the tubing in the usual manner with the means customarilyemployed.Y

It is an object of my invention is provide a method of flaring `suchtubing without rupture of the tube wall and to provide simple but highlyeffective apparatus iorpra'cticing the improved method.

The best mode in which I have contemplated applying th'e principles ofmy invention is described in the following .text and shown in theaccompanying drawings, but the latter are to be deemed merelyillustrative for it is intended that the patent shall cover by suitableexpression in the claims whatever features of patentable novelty existin `the invention disclosed.

in the accompanying drawings,

Figure 1 is an exploded 'View of the several parts of a preferred formof apparatus for flaring tubing in accordance with my improved method;

Figure 2 is a medial section showing the vparts oi' my improvedapparatus and a piece o'ftubing in thel relative positions they occupywhen the flaring operation is about to be performed;

Figure 3 is a section on line 3 3 of Figure 2;

Figures 4, I5 and 6, show the tubing and immediately adjacent parts ofthe apparatus in their relative positions at different stages of thedaring operation;

Figure '7 shows the end of the tubing as it gen-k erally appears whenremoved from the apparatus; and

Figure 8 shows the nnished "flared end.

The essence of my improvedmethod resides in holding the externalVsurface of a portion adjacent the lend of the tubing to a diameter lessthan the greatest diameter of the external surface o'f the dared portionof the tubing. The thickness of the wall kclose by the end is reduced,however, and vpart of the wall material is swaged downward slightly intothat portion of the tubing which is dared. By` thus holding the edge ofthe tube from any substantial expansion, coupled with the slightupsetting or swaging of the material toward where the greatest stretchof the tubing will normally occur, it is possible to flare the presentavailable tubing without rupture or weakening of the tube wall.

Referring -now to Figure l, vthere is shown in separated relation thevarious parts of a pre- 2 ferred form of flaring means for practicing myinvention. These comprise a block or clamping ring I0, a pair of jawholders I2, I4, a pair of ila-ring jaws I 6, I8, and a aring plunger 20.

The block I d may be secured in a vise but its outer` lsurface isknurled so that it can rbe held in ones hand. It has a tapered axialhole Illa extending through it.

The jaw holders I2, lll have exterior curved surfaces I2a, Ida taperedto fit the wall of the hole Illa in the clamping ring It, and also haveopposed dat surfaces I2b and hib. Each holder has a semi-cylindricalrecess I2c, Ic which terminates in an enlargement i211, Ild at the upperend to provide a shoulder I2e, Ite. When the holders are together theyprovide a cylindrical hole between them for 'the reception of theliaring jaws I5 and I8'.

These jaws have 'external cylindrical surfaces Ilia, Ilia and externalshoulders Ib, Ib to fit the hole formed by the holders I2, Hi. Aclamping jaw may be held toa holder by a screw 22, whose threadedportion passes through a shouldered hole in the holder and screws into atapped hole in the jaw. Each jaw hasfor most of its length asemi-cylindrical recess Ic, ISC, but at its upper end is particularlyformed with tapered surfaces ltd, Id which diverge outward at an anglefrom the axis equal to one-half the degree of flare to be imposed on thetubing 24. Each outwardly 'tapered surface Idd, I8d extends Ialong theaxis as far as desired to` make the length of the flare wanted. From thering of greatest diameter of the outwardly flared surface, the wall istapered inward sharply, as at It'e and Ie, to terminate in a shortcylindrical portion It?, Itf, a little larger than the outside dimensionof the unared tube.

The vfla-ring plunger 2d has a cylindrical portion 2da substantially thesame size as the hole in the tubing to be flared. From this portion, toanother cylindrical portion Zlib, is a tapered or flaring surface 2demaking 4an angle with the axis of the plunger equal to the degree offlare to be imposed on the tubing. The diameter of the largercylindrical portion 26D of the plunger is slightly less than that of theshort cylindrical hole formed by the portions IBf and ISf of the flaringjaws.

In the practice of my improved method the tubing 24 to be flared isplaced between the jaws I6 and I8 with its end 24a extending slightlybeyond the ends of the jaws as shown in Figure 2. The jaws are set inthe holders I2 and I4 and the latter in the ring I il. The larger endsof the holders are ,preferably tapped lightly with a hammer to tightenthe jaws against the tubing. The plunger 2i] is inserted in the tubingwith its flared portion 20c resting on the edge 24a of the tube. Thelatter edge, by the way,

need not be out or finished with any special care but maybe the edgeleft when tubing is out with a hack saw or pipe cutter.

The plunger is now subjected to hammer blows until the aring iscompleted. In Figures 4, 5V

and 6 I have attempted to illustrate what I believe occurs as theflaring takes place. As the plunger is driven into the tubing theholders l2 and I4 settle very firmly into the ring I0, causing the jawsIS and I8 to grip more tightly the tubing 24 between them. As the flaredsurface 20c of the plunger moves downward it acts with swaging effect onthe tube wall, gradually thinu ning it opposite the portions lf and I8fof the jaws. Part of the metal displaced by the swaging action may moveupward to swell very slightly the edge 24a of the tubing, but for themost part it moves downward and apparently slightly thickens the tubingjust below the said portions if and I8f of the jaws.

As the progress of the plunger continues, the

. tube is forced outward into the space around it,

formed by the tapered surfaces ld, ld, le and l8e, until when theplunger bottoms (that is, when the lower end of its flared portion isopposite the lower ends of the flared portions of the flaring jaws) thewall of the tube is flared outward desired and as shown in Figure 6.

'The holders I2 and I4 can then be tapped lightly at their smaller endto free them from the ring, the latter can be slipped downward, and theholders and jaws separated to remove them from the tubing. Either beforethis is doneor afterward the plunger can be withdrawn'from the tubing.The end of the tubing will appear generally as shown in Figure 7 and thefinal step is to clean off the necked portion 24h and edge 24a and thusproduce the finished flared end 24e shown in Figure 8.

Examination of the ared end discloses no rupture, tear or crack in thetubing. The entire flared portion is intact. If anything, it may beslightly stronger than would be the case if ared in the usual way,because despite the increased circumferential size, the wall thicknessof the flared portion is not appreciably thinned but usually measures asthick as the original thickness of the tube wall.

I claim:

1. Means for flaring tubing comprising a die having a cylindrical wallfitting the normal external wall of the tubing, a conically flared wallfor determining the degree of flare of the tubing, and ak shortcylindrical wall adjacent the large end of said flared wall providing anopen--A ing slightly larger than the external dimensions of the tubing;and a plunger for insertion in the tubing having a conically flaredsurface whose larger end is slightly smaller than the said openingwhereby upon the plunger being inserted into the tubing until the saidlarger end of the flared surface of the plunger is opposite thesaidvshort cylindrical wall of the die, the tubing is flared against theflared surface of the die and its wall opposite the said shortcylindrical Wall 0f the die is appreciably thinned. I

2. Means for forming a conical flared end on tubing comprising a diehaving a cylindrical section fitting the normal external wall of thetubing, a conical section diverging outward from the end of thecylindrical section and a conical surface converging inward from thelarger end of the diverging conical section, and a plunger for insertionin the tubing having a leading cylindrical section fitting the normalinternal wall of the tubing and a conical section diverglng outward fromthe end of the cylindrical section; the diverging conical section of theplunger having its largest external diameter substantially the same asthe smallest internal diameter of the inwardly converging conicalsection of the die,

whereby the conical section of the plunger and the converging conicalsection of the die effect a swaging of the tubing as the plunger isinserted therein.

3. Means for forming a conical flared end on tubing comprising a diehaving a cylindrical surface fitting the normal external wall of thetubing, a conical surface diverging outward from the end of the saidcylindrical surface, a conical surface converging inward from the end ofthe diverging conical` surface, and a short cylindrical surfaceextending from the end of the converging conical surface; and a plungerfor insertion in the tubing having a leading cylindrical surface fittingthe normal internal wall of the tubing, a conical surface divergingoutward from the end of the last said cylindrical surface, and a secondcylindrical surface extending from the end of said diverging conicalsurface; the diameter of the said second cylindrical surface of theplunger being substantially the same as the diameter of the said shortcylindrical surface of the die.

4. Means for forming a conical flared end on tubing comprising a diehaving a cylindrical surface fitting the normal external wall of thetubing, a conical surface diverging outward from the end of saidcylindrical surface for determining the flared end desired, a reentrantsurface at the larger end of said conical surface having its smallestdiameter substantially the same as the diameter of the normal externalwall of the tub- I ing; and a plunger for insertion in the tubing havinga cylindrical surface fitting the normal internal wall of the tubing, aconical surface diverging outward from the end of the last saidcylindrical surface to a diameter only slightly smaller than the saidsmallest diameter of the reentrant surface of 'the die; the saidreentrant surface of the die and the conical surface of the plungercoacting to swage the tubing as the plunger is inserted, therebymaintaining the wall of the flared end of the tubing substantially atthe same thickness as that of the unflared tubing wall and causing thetubing between the said reentrant wall and the conical surface of theplunger having the largest diameter to be appreciably thinned.

JAMES R. WELSHMAN.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 410,000 Matheson Aug. 27, 18891,791,887 Davies et al. Feb. 10, 1931 1,817,854 Sorenson Aug. 4, 19311,724.920 Fischer Aug. 20, 1929 1,804,815 Schultis May 12, 19312,024,803 Nelson Dec. 17, 1935 412,389 Isherwood Oct. 8, 1889 606,046Chillingworth June 21, 1898 FOREIGN PATENTS Number Country Date 5,500Great Britain Mar. 11, 1896

